Machine tool for the edge machining of a workpiece

ABSTRACT

The invention is directed to a machine tool for edge machining a workpiece. The machine tool includes a drive unit for a rotary tool, a guide device for guiding the workpiece in a horizontal infeed direction and a chip collecting hood. The guide device includes an upper pressure element and a lower pressure element and one of the pressure elements is settable in the vertical direction relative to the other pressure element and also the drive unit. The chip collecting hood includes a side wall having a cutout for receiving an edge region to be machined of the workpiece. The side wall includes a base wall part and a closure wall part. The base wall part is positioned fixedly relative to the drive unit and the closure wall part is positioned fixedly relative to the pressure element to be settable in the vertical direction. The closure wall part delimits the cutout in the vertical direction.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority of European patent application no. 16002 692.8, filed Dec. 19, 2016, the entire content of which isincorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a machine tool for the edge machining of aworkpiece.

BACKGROUND OF THE INVENTION

The edge machining or workpieces made of wood or wood-like material suchas chipboards, floor panels or the like is associated with a high degreeof chip production. The chips have to be removed as promptly andcompletely as possible from the point of origin, that is, from where thetool cutting edges come into engagement with the workpiece edge, andcarried away. Otherwise, they can have various disadvantageous effects,such as multiple chipping, development of heat, formation of impressionson the workpiece surface or the like.

Guide devices for guiding the workpiece along the circumferentialcontour of the rotary tool are provided in the prior art. Such guidedevices comprise at least two pressure elements that are locatedopposite one another in a vertical direction, specifically an upperpressure element and a lower pressure element, between which theworkpiece is held and guided. At least one of the two pressure elementsis settable in the vertical direction relative to the respectively otherpressure element and also relative to the drive unit, in order that thedesired edge profile arises at the right point on the workpiece.

Furthermore, use is made of chip collecting hoods which are fastened tothe drive unit and cover the tool and the cutting region. A connectedsuction fan is intended to extract the chips in a controlled manner. Amachine tool having such a chip collecting hood is known from U.S. Pat.No. 8,074,688. Therein, the edge of a workpiece is machined by upcutmilling by means of a rotary tool. The rotary milling tool and also theedge region of the workpiece are enclosed virtually tightly by the chipcollecting hood in order to ensure good extraction. In particular thatregion of the hood that immediately adjoins the workpiece edge isproblematic. Not only does the chip collecting hood have to allow theworkpiece to be guided up to the cutting region of the rotary tool, thehood also has to reach as close as possible to the workpiece surface inorder to prevent chips escaping in an undesired manner there. For thispurpose, the side wall of the chip collecting hood has a cutout whichencloses the cross section of the workpiece edge with a slight gap.

In upcut operation, the chips removed from the workpiece are flung awayat an oblique angle relative to the workpiece edge. A considerableproportion of the flung-away chips does not directly reach theabovementioned gap and can be extracted. However, it is not possible toprevent a certain proportion of chips from passing out undesirablythrough the gap. This problem is even more pronounced when the machineworks in downcut operation. In this case, the removed chips are flungaway substantially parallel to the workpiece edge immediately after theyhave been produced, with the consequence that they reach the gap more orless directly in a high concentration and can emerge there.

In practical operation, such machine tools have to be able to beoperated universally and are therefore provided with different settingcapabilities. Upon changing between workpieces of different thickness,the circumferential wall and the cutout formed therein also have to beadapted in the height or vertical direction in order to maintain assmall as possible a vertical gap dimension between the workpiece surfaceand cutout edge. The same goes in a corresponding manner in the event ofa correction of the spacing between the drive unit and workpiece edge.If, for example, the radius of the tool is reduced during sharpening,this is associated with a reduction in diameter, as a consequence ofwhich the spacing dimension has to be corrected. Since the hood isfastened to the drive unit, the cutout is also displaced, together withthe drive unit, relative to the workpiece edge. Consequently,complicated correction of the cutout in the hood wall is also necessaryin the depth direction.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a machine tool wherein areliable chip guidance is possible even in the case of varying operatingconditions.

The machine tool of the invention is for the edge machining of aworkpiece having an edge region. The machine tool includes: a rotarytool defining a vertical rotational axis; a drive unit for driving therotary tool about the rotational axis; a guide for guiding the workpiecein a horizontal infeed direction so as to permit machining thereof bythe rotary tool; a collecting hood for collecting chips generated by themachining of the workpiece; the guide including mutually opposite upperand lower pressure elements arranged in a vertical direction for contactengaging the workpiece; at least one of the upper and lower pressureelements being adjustable in the vertical direction relative to theother one of the upper and lower pressure elements as well as relativeto the drive unit; the collecting hood having at least one side wallextending transversely to the horizontal infeed direction; the side wallhaving a cutout for accommodating the edge region of the workpiece to bemachined; the side wall being made up of a base wall part fixedlypositioned relative to the drive unit and a closure wall part fixedlypositioned with respect to the one pressure element so as to beadjustable in the vertical direction therewith and to at least partiallyoverlap the base wall part; and, the closure wall part delimiting thecutout at least in the vertical direction.

According to the invention, provision is made for the side wall of thechip collecting hood to be made up of a base wall part and at least oneclosure wall part, the base wall part being positioned fixedly relativeto the drive unit, and the at least one closure wall part beingpositioned fixedly relative to the adjustable pressure element. Thefixed relative positioning of the closure wall part is configured suchthat the closure wall part is settable, or adjustable in its position,in the vertical direction together with the associated pressure elementand in the process at least partially overlaps the base wall part.Furthermore, the at least one closure wall part bounds the cutout forthe edge region of the workpiece at least in the vertical direction.

This means, in other words, nothing more than that the closure wall partis adapted in shape and height position to a particular workpiece edgeprofile and is then fastened. As a result, a boundary of the cutoutarises in the vertical direction with a fixedly defined gap dimension,measured in the vertical direction, between the cutout edge andworkpiece surface. This gap dimension can be set in a suitable manner inorder that the workpiece can pass through cleanly and without gettingstuck and in order to bring about tightness with respect to chip escapethat is as distinct as possible. If, now, during ongoing operation, achange has to be carried out between two or more different workpiecethicknesses, a corresponding height adaptation of the associatedpressure element will take place. However, this height adaptation isassociated also with height adaptation of the associated closure wall.Consequently, this ensures that the previously selected vertical gapdimension that is considered suitable is maintained automatically.Adaptation work on the extraction hood is not necessary. The overlap ofthe closure wall part with the base wall part ensures sufficienttightness against chip escape at this point, too, in spite of themultipart configuration. Overall, the adaptation complexity on changingbetween different workpiece thicknesses is limited to adaptation work onthe particular pressure element of the guide device, without the hood assuch having to be taken into consideration. Nevertheless, the collectingand guiding function of the chip collecting hood is fully retained uponchanging between different workpiece thicknesses.

In practical operation, upon changing between different workpiecethicknesses, only one of the two pressure elements, specifically theupper pressure element, is set in terms of its height position.Accordingly, it may be sufficient also to fasten an above-describedclosure wall part only to this one pressure element. In a preferredembodiment of the invention, however, an upper closure wall and a lowerclosure wall part are provided, which each proportionately bound thecutout, the upper closure wall part being positioned fixedly relative tothe upper pressure element and the lower closure wall part beingpositioned fixedly relative to the lower pressure element. As alreadydescribed above, the designation “positioned fixedly” applies hereinasmuch as relative positioning of the closure wall parts to therespectively associated pressure element has to be carried out onlyduring the basic setup of the machine and is then no longer changed. If,however, in individual cases or as part of the machine setup, it isnecessary to adapt the height also of the second, in this case of thelower pressure element, the same advantageous effects occur as in thesetting of the upper pressure element, already described above. The samegoes in a corresponding manner also when the position of the drive unitor the tool is adapted in the vertical axial direction, together withthe hood part fastened thereto, relative to the workpiece edge. Verticaladaptation of the cutout in the side wall is not necessary, since thecutout geometry that has already been selected is maintained as a resultof the closure wall parts.

In a preferred embodiment, the cutout for the edge region of theworkpiece is also bounded toward the base wall part in a depthdirection, perpendicular to the vertical direction and perpendicular tothe infeed direction, by at least one closure wall part. As a result, itis possible for also the horizontal spacing between the tool drive andguide device or workpiece edge to be able to be corrected or set,without the gap dimension, measured in the depth direction and set asdesired, between the cutout edge and workpiece edge changing.

It may be expedient for one closure wall part or the plurality ofclosure wall parts to be positioned on the outside of the base wall partconnected fixedly to the drive unit. Preferably, however, the at leastone or the two closure wall parts are arranged on that side of the basewall part that faces the interior of the chip collecting hood. This hasthe result that the free wall edge that is present in the interior as aresult of the overlap exhibits as large a spacing as possible from theworkpiece and thus from the point of origin of the chips. In conjunctionwith the resultant overlap direction, penetration of chips, dust or thelike between the wall parts is avoided.

In an expedient variant, at least one horizontal cutting cover isprovided and positioned fixedly relative to the pressure element suchthat it is settable in the vertical direction together with thispressure element. In particular, an upper horizontal cutting cover and alower horizontal cutting cover are provided, the upper cutting coverbeing positioned fixedly relative to the upper pressure element, and thelower cutting cover being positioned fixedly relative to the lowerpressure element. As a result of the horizontal extension, the cuttingcovers act as channeling guiding elements which favor controlled airguidance, which guide the chips, avoiding vertical spreading, and whichfavor effective chip extraction. The at least one or the two cuttingcovers maintain their relative position, set as desired, with respect tothe workpiece surface. Changes in thickness or other changes with aninfluence on the assembly positioning have no influence on the spacingdimension between the cutting cover and workpiece surface. Chip and airguidance remain unchanged, and so these are retained in the desiredquality.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the drawingswherein:

FIG. 1 shows a perspective internal view of a machine tool embodiedaccording to the invention, with a workpiece which is guided in its edgeregion between two pressure elements, and with a multipart chipcollecting hood;

FIG. 2 shows an end-on view of the machine tool according to FIG. 1 withdetails of the side wall of the chip collecting hood, which comprisestwo closure wall parts fastened to the pressure elements; and,

FIG. 3 shows the machine tool in the view according to FIG. 1 with thetool removed and with further details relating to the arrangement of theclosure wall parts and of horizontal cutting covers.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 shows a perspective internal view of a machine tool 1 embodiedaccording to the invention for the edge machining of a workpiece 40. Themachine tool 1 is illustrated here in its normal operating positionrelative to a vertical direction 50, indicated by a double arrow, whichfor its part extends in the acting weight force direction. The workpiece40 is positioned lying horizontally, that is, at right angles to thevertical direction 50, for the edge machining and is moved in ahorizontal infeed direction 48 relative to a rotary tool 3 of themachine tool 1. Lying at right angles to the height direction 50 andalso at right angles to the infeed direction 48 is a depth direction 49,which is likewise indicated by a double arrow.

The workpiece 40 is configured in a sheet-like manner for example, here.However, it may also be in the form of strips, slats, beams or the like,for example. Provided here as the material of the workpiece 40 are woodmaterials, wherein the term “wood material” includes, in addition togrown wood, also chipboard material or other fibrous material, forexample of laminate flooring.

The machine tool 1 comprises a drive unit 2 with a vertical axis ofrotation 4, that is, an axis of rotation extending parallel to thevertical direction 50. The drive unit 2 is an electric motor here.However, it can also be some other motor or only the transmission of amotor positioned at some other location. The rotary tool 3 driven inrotation about the vertical axis of rotation 4 by the drive unit 2 isconfigured here as a milling head. However, it can also be a circularsaw blade or the like. In any case, the rotary tool 3 has a number ofcutting edges 5 on its circumference. The direction of rotation of therotary tool 3 is indicated by an arrow 47, according to which it extendsin the clockwise direction when seen from above. The workpiece 40 has anedge region 41 which extends in the infeed direction 48 and which ismachined by the machine tool 1. To this end, a guide device 6 isprovided, by means of which the workpiece 40, to be more precise theedge region 41 of the workpiece 40 is moved along the circumferentialregion of the rotary tool 3 in the infeed direction 48 such that theedge region 41 comes into contact with the cutting edges 5 and is givenits desired cross-sectional profile by chipping by the cutting edges 5.In FIG. 1, the workpiece 40 is moved to the left, that is, counter tothe direction of rotation 47, in the infeed direction 48. Consequently,that portion of the edge region 41 that is located to the left of theengagement region with the cutting edges 5 has already undergone itsprofiling, and thus upcut milling is illustrated here. In the context ofthe invention, however, downcut milling is also possible, the infeed anddirection of rotation then being in the same direction.

The guide device 6 for the workpiece 40 comprises two pressure elements7, 8 located opposite one another in the vertical direction 50,specifically an upper pressure element 7 and a lower pressure element 8.The workpiece 40 rests on the lower pressure element 8. The upperpressure element 7 bears on the workpiece 40 from above and pushes thelatter from above onto the lower pressure element 8. In this way, theedge region 41 of the workpiece 40 is fixed both in the verticaldirection 50 and in the depth direction 49, but can be moved in theinfeed direction 48 relative to the drive unit 2 or to the rotary tool3. During the setup of the machine, relative positioning of the driveunit 2 with the tool 3 relative to the lower pressure element 8 takesplace in the vertical direction 50 and in the depth direction 49, suchthat a particular desired profile of the edge region 41 arises in aparticular relative position with respect to the workpiece 40 duringchipping. For example, the wear-related re-grinding of the cutting edges5 results in a reduction in the effective tool diameter, however,requiring position correction. For such position correction, the driveunit 2 with the rotary tool 3 is moved closer to the lower pressureelement 8 in the depth direction 49. Of course, a height correction inthe vertical direction 50 is also possible in a corresponding manner.

In practical operation, it may be necessary to machine workpieces 40with changing thicknesses, but otherwise with the same milling profile.In this case, the position of the lower pressure element 8, of the driveunit 2 and of the rotary tool 3 remains unchanged, while only heightsetting or height adaptation of the upper pressure element 7 is carriedout by means of a schematically indicated height adjuster 20.

As shown in FIG. 1, the region of the rotary tool 3 and the engagementthereof with the edge region 41 of the workpiece 40 is enclosed by achip collecting hood 9. The chip collecting hood 9 has, in its directionfacing the guide device 6 or the workpiece 40, an open side 13 andotherwise represents a closed housing. To this end, it comprises a topwall 11 positioned above the rotary tool 3 and a bottom 12 positionedbeneath the rotary tool 3. Furthermore, it comprises at least one sidewall 10, which is located here in the plane defined by the depthdirection 49 and the vertical direction 50 and consequently extendstransversely to the infeed direction 48. On the opposite side, facingthe observer here, such a side wall is likewise provided. Although thisis not illustrated here for greater clarity, it is embodied in the sameway according to the invention. The following description of the sidewall 10 illustrated in the drawing thus applies equally to theconfiguration according to the invention of the further side wall thatis not illustrated. Otherwise, the chip collecting hood 9 comprises, onthe front side located opposite the guide device 6, a wall which is notillustrated here, likewise for greater clarity. Finally, it should alsobe mentioned that the chip collecting hood 9 reaches with its open side13 as far as the guide device 6. The open side 13 is covered by theguide device 6 or by the upper and lower pressure elements 7, 8, suchthat the interior of the chip collecting hood 9, in which the rotarytool 3 and the edge region 41 to be machined of the workpiece 40 arelocated, is closed off substantially hermetically.

FIG. 2 shows a side view of the machine tool 1 according to FIG. 1.Here, it is first of all shown that a schematically indicated suctionfan 21, by means of which the chips that arise during the machining ofthe edge region 41 are extracted from the interior of the chipcollecting hood 9, is connected to the interior of the chip collectinghood 9.

It is furthermore readily apparent from the side view according to FIG.2 that the edge region 41 to be machined of the workpiece 40 is heldbetween the two pressure elements 7, 8 and in the process protrudes intothe interior of the chip collecting hood 9. Since the workpiece 40 ismuch longer in the infeed direction 48 (FIG. 1) than the lateral extentof the chip collecting hood 9, the side wall 10 of the chip collectinghood 9 is provided with a cutout 14 which receives the edge region 41 tobe machined of the workpiece 40. The cutout 14 is adapted in terms ofshape and size to the cross section of the edge region 41 such that aparticular gap dimension of the desired size remains between the cutoutedge and the workpiece surface.

In order to maintain the contour adaptation, achieved in such a way, ofthe cutout 14 to the cross section of the edge region 41 under thechanging operating conditions described in connection with FIG. 1, amultipart configuration of the side wall 10 is provided according to theinvention. The side wall 10 consists specifically of a base wall part 15and at least one, in this case two closure wall parts 16, 17. The basewall part 15, the rear wall 22, the upper top wall 11 and the bottom 12together form a hood main body of the chip collecting hood 9 and arefastened to the drive unit 2, that is, positioned fixedly relative tothe latter. The abovementioned parts of the hood main body are thusadjusted together with the drive unit during an adjusting operation. Ina variation, the upper closure wall part 16 is positioned fixedlyrelative to the upper pressure element 7 such that it is settable in thevertical direction 50, or is adjustable in its height position, togetherwith the upper pressure element 7. In other words, the upper pressureelement 7 and the upper closure wall part 16 form a structural unit, theheight position of which is set jointly in the vertical direction 50upon actuation of the height adjuster 20. To this end, the upper closurewall part 16 can be screwed for example fixedly to the upper pressureelement 7. However, within the scope of the invention, such a connectionbetween the closure wall part 16 and the upper pressure element 7 isalso possible such that a relative movement between the upper pressureelement 7 and the upper closure wall part 16 is possible in the infeeddirection 48 (FIG. 1). The upper pressure element 7 can then be moved inthe infeed direction 48 (FIG. 1) together with the workpiece 40, whilethe closure wall part 16 maintains its position in the infeed direction48 (FIG. 1). Joint adjustment then takes place only in the verticaldirection 50.

Optionally, in the embodiment shown, the second, in this case lowerclosure wall part 17 is provided, which is connected, analogously to theupper closure wall part 16, to the associated, in this case lowerpressure element 8 such that it is positioned fixedly relative to thelatter. In the event of position adjustment of the drive unit 2 togetherwith the abovementioned hood main body and/or of the upper pressureelement 7 together with the upper closure wall 16, the structural unitmade up of the lower pressure element 8 and the lower closure wall 17maintains its position. Conversely, during position adjustment of thelower pressure element 8, the lower closure wall part 17 is alsoadjusted in the same way.

The two closure wall parts 16, 17 overlap one another and each also atleast partially overlap the base wall part 15, as is additionally shownin FIG. 3. Furthermore, it is apparent from FIG. 2 that the upperclosure wall part 16 bounds the cutout 14 upwardly in the verticaldirection 50 with its lower edge. The lower closure wall part 17 hassuch an edge profile that it bounds the cutout 14 downwardly in thevertical direction 50 and furthermore also in the depth direction 49toward the base wall part 15. Of course, an analogous configuration ofthe upper closure wall part 16 is also possible such that the latter, incombination or as an alternative to the lower closure wall part 17,bounds the cutout 14 toward the base wall part 15 in the depth direction49. In the preferred embodiment shown, the cutout 14 is thus enclosedonly by edges of the closure wall parts 16, 17, without the base wallpart 15 playing a role here. If, therefore, a workpiece 40 with agreater or smaller thickness is intended to be machined, the upperpressure element 7 is raised or lowered in the vertical direction 50,together with the upper closure wall part 16, by the dimension of thechange in thickness. In the process, the vertical edge spacing of theclosure wall part 16 with respect to the surface of the workpiece 40 isretained in the region of the cutout 14. Furthermore, the position ofthe drive unit 2 together with the rotary tool 3 (FIG. 1) in the depthdirection 49 relative to the functional unit made up of the two pressureelements 7, 8 and the workpiece 40 guided therebetween can be correctedor set. However, a change in position associated therewith concerns onlythe base wall part 15 of the side wall 10, but not the two closure wallparts 16, 17. Thus, the gap dimension measured in the horizontal depthdirection 49, or the horizontal edge spacing between the closure wallparts 16, 17 and the workpiece 40 is retained in the region of thecutout 14.

Overall, what is achieved is that, irrespective of all possible settingand adaptation operations, the selected adaptation of the shape of thecutout 14 to the cross section of the edge region 41 of the workpiece 40is retained. No replacement parts or format parts are required.Nevertheless, the gap dimension between the cutout edge and theworkpiece surface can be kept small enough that virtually no chipsescape from the interior of the chip collecting hood 9. This is achievednot only in the comparatively non-critical state of upcut millingaccording to FIG. 1, in which case the chips are then flung toward theright, at an oblique angle to the workpiece edge, against the region ofthe right-hand closure wall parts 16, 17. Rather, the sealing action isretained even in downcut operation, when the chips that have just beenremoved are flung away tangentially and parallel to the workpiece edge,directly toward the cutout 14.

FIG. 3 shows the machine tool 1 according to FIGS. 1 and 2 in theperspective view according to FIG. 1 but with the rotary tool 3 removed.It can be seen here that the two closure wall parts 16, 17 are arrangedon that side of the base wall part 15 that faces the interior of thechip collecting hood 9. On this inner side, they overlap the base wallpart 15 without a gap. Furthermore, they overlap one another in thevertical direction 50 such that a closed side wall 10 is formed overall.Of course, however, it is also possible to arrange one of the twoclosure wall parts 16, 17 or even both closure wall parts 16, 17 on theouter side of the base wall part 15.

It is also clear from viewing FIGS. 1 and 3 together that the machinetool 1 has, at least in the interior of the chip collecting hood 9, ahorizontal cutting cover 18, 19. In the preferred embodiment shown, anupper horizontal cutting cover 18 and a lower horizontal cutting cover19 are provided. Analogously to the above-described closure wall parts16, 17, the upper cutting cover 18 is positioned fixedly relative to theupper pressure element, while the lower cutting cover 19 is positionedfixedly relative to the lower pressure element. Irrespective of all thesetting operations already described above, the cutting covers 18, 19retain their predefined relative position with respect to the workpiecesurface as a result. In the specific configuration, the horizontalcutting covers 18, 19 are formed by flat elements which each extend inthe horizontal plane defined by the infeed direction 48 and the depthdirection 49 and are thus parallel to the flat sides of the workpiece40. Between the two horizontal cutting covers 18, 19, the rotary tool 3rotates during operation such that the chips produced thereby can beguided between the two cutting covers 18, 19 and fed in a controlledmanner to the suction fan 21 (FIG. 2). In particular the verticalspacing of the two cutting covers 18, 19 with respect to the workpiecesurface remains the same even when workpieces 40 of differentthicknesses are machined, such that the chip guiding action also remainsunchanged.

In the specific configuration, an L-shaped profile is provided for theupper cutting cover 18, the horizontal leg of which engages under theupper top wall 11 into the interior of the chip collecting hood 9 andforms the upper cutting cover 18. The vertical leg of the L-shapedprofile covers the gap region between the height adjuster 20 and theupper pressure element 7, specifically irrespective of the correspondingset height position of the upper pressure element 7. The horizontal legforming the upper cutting cover 18 is illustrated here such that it islocated immediately beneath the upper top wall 11. However, it can alsobe positioned further down, closer to the workpiece 40. In the case ofthe lower cutting cover 19, a horizontal guide plate is provided, whichis fastened to the lower pressure element 8 by means of screw-onbrackets, or is screwed thereto. Otherwise, the lower closure wall part17 is fixedly connected to the lower cutting cover 19, while the upperclosure wall part 16 is fixedly connected to the upper cutting cover 18,such that, in this regard, the same relative positioning is alwaysmaintained.

It was already mentioned at the beginning that the multipartconfiguration applies equally for the one side wall 10 shown here andfor the opposite side wall that is not illustrated here. However, in thecontext of the invention, it may be sufficient to configure only oneside wall 10 in the manner according to the invention, it thenpreferably being that side wall 10 that is located immediately behindthe engagement region between the rotary tool 3 and the workpiece 40with regard to the direction of rotation 47, and which is thus reacheddirectly by the stream of chips that are produced. On the opposite side,which is subjected to fewer chips, a different wall construction may besufficient.

It is understood that the foregoing description is that of the preferredembodiments of the invention and that various changes and modificationsmay be made thereto without departing from the spirit and scope of theinvention as defined in the appended claims.

What is claimed is:
 1. A machine tool for the edge machining of aworkpiece having an edge region, the machine tool comprising: a rotarytool defining a vertical rotational axis; a drive unit for driving saidrotary tool about said rotational axis; a guide for guiding theworkpiece in a horizontal infeed direction so as to permit machiningthereof by said rotary tool; a collecting hood for collecting chipsgenerated by the machining of the workpiece; said guide includingmutually opposite upper and lower pressure elements arranged in avertical direction for contact engaging the workpiece; at least one ofsaid upper and lower pressure elements being adjustable in said verticaldirection relative to the other one of said upper and lower pressureelements as well as relative to said drive unit; said collecting hoodhaving at least one side wall extending transversely to said horizontalinfeed direction; said side wall having a cutout for accommodating theedge region of the workpiece to be machined; said side wall being madeup of a base wall part fixedly positioned relative to said drive unitand a closure wall part fixedly positioned with respect to said onepressure element so as to be adjustable in said vertical directiontherewith and to at least partially overlap said base wall part; and,said closure wall part delimiting said cutout at least in said verticaldirection.
 2. The machine tool of claim 1, wherein said closure wallpart is a lower closure wall part; and, wherein said machine toolfurther comprises an upper closure wall part; said lower closure wallpart and said upper closure wall part conjointly delimit said cutout;and, said upper closure wall part is fixedly positioned relative to saidupper pressure element and said lower closure wall part is fixedlypositioned relative to said lower pressure element.
 3. The machine toolof claim 1, wherein said closure wall part delimits said cutout towardsaid base wall part in a direction lying perpendicular to said verticaldirection and perpendicular to said infeed direction.
 4. The machinetool of claim 1, wherein said collecting hood defines an interior spaceand said base wall part has a side facing toward said interior space;and, said closure wall part is arranged on said side of said base wallpart.
 5. The machine tool of claim 1, further comprising at least onehorizontal cutting cover fixedly positioned relative to said one of saidpressure elements so as to be adjustable in said vertical direction incommon therewith.
 6. The machine tool of claim 1, further comprising: anupper horizontal cutting cover and a lower horizontal cutting cover;said upper horizontal cutting cover being fixedly positioned relative tosaid upper pressure element; and, said lower horizontal cutting coverbeing fixedly positioned relative to said lower pressure element.